Carboxymethyl cellulose (CMC) is used in mineral processing as a flotation depressant. One and the same CMC is used as a flotation depressant in the different flotation processes in a mineral processing plant. A mineral processing plant uses one and the same CMC for any one of their flotation processes and the characteristics of the CMC used is always the same and depends on the ore and desired characteristics of the plants final concentrate. Thus, the CMC used at one plant has only one characteristic.
CMC is mainly for the depression of carbonate and talcaceous gangue in the flotation of Cu—Ni sulfide ores. In recent years applications have also been found in the beneficiation of platinum group metal (PGM) ores. CMC has been tested for the separation of coal from pyrite and it is reported as a selective depressant in the flotation of salt-type minerals, as a slime depressant in potash flotation and as a selective depressant in differential sulfide flotation.
Depression of talc and readily floatable magnesia-bearing minerals in nickel flotation has been carried out for years, particularly in Canada, Australia and Southern Africa. Polysaccharides in the form of natural gums, and starches and dextrin-type compounds have been the most commonly used depressants. The use of carboxymethyl cellulose reagents have been known in copper-nickel flotation since the early 1950's when research was conducted in the USSR.
Although CMC is a depressant which can be used in the flotation of ores, understanding the interaction mechanisms between CMC and mineral particles in different flotation circuits and different pulp conditions is still limited. A better understanding of these mechanisms is desired in order to optimize the flotation process and make it more cost-effective. More knowledge about the importance of structural features of CMC in flotation processes is also desired.
Even the smallest improvement in the flotation process has a large impact on the total costs of mineral processing, because the flotation process gives a certain initial percentage of the desired minerals and this percentage is what the remaining downstream processes have to work with. A higher concentration of the desired mineral in the concentrate of the flotation process is desired (for a given recovery of that mineral). To be able to influence the concentrate is important for mineral processing. It is desirable to influence the flotation performance, for example increasing or decreasing the mineral content of the concentrate. A decrease in the amount of CMC is desired.
The present disclosure is directed to overcoming one or more of the problems as set forth above.